I guess I feel the need to jump into this argument...not sure why but whatever...I have Sidis and honestly I have an issue or 2 with them. My current gripe is that the inside of the ratchet strap (not that ratcheting part but the other end) snags on my crank arms fairly frequently when I am climbing out of the saddle. I like the design of the Specialized shoes better in this area of the shoe (not that they are the only shoe like that but my LBS sells them so...).

Everything I have heard and read says the Pro Carbon is a VERY fine shoe.